[Development] [HiDPI] Rethinking the scaling algorithm

[Allan Sandfeld Jensen]

On Tuesday 08 November 2016, Niccolò Belli wrote:
> 1) Always round down. With your current formula a 145ppi screen gets scaled
> by a 2x factor, while every other toolkit (GTK3 for example[3]) starts
> scaling at 192ppi. This is also what people expect and it would return the
> correct 2x scaling factor for my laptop. So the formula should be
> scaling_factor=qRoundDown(yourDpi/96)
> 
We have a two factor scaling system. We also scale by DPI. 144/2 == 72 for 
instance, which happens to be the standard on Macs. Therefore 144DPI become a 
normal 2x scaling of standard 72 Mac DPI. 

And having 2x with smaller text, is a lot better than 1x with large text on a 
27" 4K desktop screen.

`Allan